Can aquaculture help Groote Eylandt survive its transition from manganese mining?

Groote Eylandt – a remote outpost in the Gulf of Carpentaria – is a place of marked contrasts. Teeming with wildlife, it’s one of the country’s top sport fishing destinations, home to hundreds of saltwater crocodiles and a handful of indigenous Aboriginal communities. Yet, since the 1960s, the island’s economy has been almost entirely reliant on one of the world’s largest manganese ore deposits – deposits that have spawned an open-cut strip-mining operation relying on diesel generators for power since then.

“The mine is everything. Without it there wouldn't be a post office, there wouldn't be a police station, there wouldn't be a supermarket. The list goes on and on and on. It contributes so much to the economy,” reflects Dr Valentin Thépot, aquaculture manager at Groote Aqua Aboriginal Corporation.

Operational since the 1960s, the mine is earmarked for closure in the next 5-10 years, bringing an end to the steady flow of royalties. But Thépot sees the island as having genuine potential to provide opportunities for an indigenous population that has lived off the sea for thousands of years.

“The sea’s resources are so amazing here that if we manage them properly through aquaculture and small fisheries, it will provide for the future of the Anindilyakwa people, just like it did in the past. We're not reinventing the wheel here, just giving it a modern twist, that was the thinking for us and the traditional owners of Groote Eylandt, through the Anindilyakwa Land Council,” he explains.

Indeed, Groote Eylandt has a rich history of trading seafood: fishing crews from Makassar — a port on the Indonesian island of Sulawesi — arrived in numbers from the 17th century onwards. They had the blessing of the island’s Traditional Owners, who exchanged pearls and sea cucumbers for goods such as cloth, rice and knives. While the trade was brought to an end by restrictive government polices in the early 20th century, it has left its mark in the contemporary culture, language and art of the local community and Thépot sees the project as a continuation of this tradition.

He arrived on Groote following a decade of researching the farming of a range of low trophic native Australian species. And, since taking the job, has been leading a team trialling the production of a range of promising species across different groups including echinoderms, molluscs, fish and seaweeds.

“We didn’t want to limit ourselves to the main species that are cultured in Australia – Humpty Doo barramundi produces thousands of tonnes a year of premium barramundi and we can't compete with them because they're on the mainland and closer to market than we are. But we have some very unique species that have high value: sea cucumber made its way to our aquaculture licence pretty quickly, based on local abundance and historical and cultural significance. We are also growing blacklip oysters, sea grapes, Asparagopsis, a few other Gracilaria-like species of seaweed, rabbitfish and - soon - black jewfish,” he explains.

The latter are highly prized for their swim bladders in the Chinese traditional medicine market, spawning an illicit trade that is devastating wild populations.

“Poachers take the bladders, which are worth $500-$900 per kilogram, and discard the dead fish, so it's a wasted resource. For us the meat would also be a by-product, but it could feed local community members,” Thépot reflects.

Meanwhile they plan to grow sea cucumbers in large ponds, and add rabbitfish – a herbivorous species – to ensure that the cucumbers, which eat organic matter associated with the sand, have optimal growing conditions.

“If you have a seaweed carpet at the top of the pond, you don't have light penetration. You don't have the food for the sea cucumbers. So our idea is to put rabbitfish in to clean the ponds for us. So that's less of a cost for us and at the same time you get extra - and delicious - protein being grown in those ponds, again to sustain the local population,” Thépot observes.

“I don't really like the term multi-trophic aquaculture. It's more integrated low trophic aquaculture, ‘same, same but different’ as they say in Australia. And I'm a big fan of extractive low trophic species and minimising the amount of waste through polyculture. ‘Nothing is lost, nothing is created, everything is transformed’, credited to Anthoine Lavoisier, is my favourite quote. and this is how we operate our site,” he adds.

The corporation currently has a 7 hectare lease, but are only occupying about 1 hectare of this and operate their recirculating aquaculture systems (RASs) to run various R&D projects tailored towards developing a path for future production. This includes broodstock maturation, larval rearing and growth trials. The species investigated in those systems are blacklip oysters (S. echinata), sandfish (H. scabra), seaweed (mostly Caulerpa spp.) and rabbitfish (S. lineatus).

“Our four RASs (~100,000L in total) are amazing tools for us to manipulate and control all key chemical, physical and biological parameters for the different species we’re working on. It's also a tank-based and zero discharge system. Everything is filtered through different species, mainly seaweed, that can clean the water for us, so we can recirculate the water back to the key species that we have. We live on an island (and planet) with limited resources, we humans cannot keep on operating on a linear model. There is no such thing as waste, just resources for different purposes,” Thépot explains.

However, as they edge towards commercial production they’ve applied to the Northern Territory Environmental Protection Agency to be able to add nine 350m² ponds and one 1ha bioremediation pond.

“This next stage of development will be key to add scale and commercial capacity for us. As for the RASs we are planning on copying nature as much as possible and use gravity-fed systems with complementing species so the waste from one is the feed for the next,” notes Thépot.

Life on Groote

It’s a role – and an island – that Thépot has embraced, although he admits that his enthusiasm is not shared by all his recruits.

“I always try to, excuse my French, scare the shit out of my future employees and say, look, there's no nightclubs, no malls, limited social life, but there is plenty of crocodiles, sharks and stingers. But for those that are brave enough, and make the move to Groote Eylandt, they realise that although different from the mainland, there are plenty of social activities, three pubs, lots of fishing. Yes there are crocs and sharks but it’s the NT, respect it and you’ll get to enjoy it fully. Some of my staff scuba dive and spearfish here. Once you break the ice with the locals it's a very close community,” reflects Thepot, whose enthusiasm for the island is matched by his wife and three young daughters.

In terms of staff he has two to three full timers and seven casual staff, of whom the majority are Traditional Owners.

“I'd love to be able to offer them full time contracts but it's not really part of their culture, so casual contracts suit them and us quite well. It took me a while to wrap my head around it – as a manager in aquaculture you've got species that need daily monitoring and there are some things that need to happen at specific times – but we’ve learned a lot from them as well,” he explains.

Natural hazards are another concern.

“Everything is pond-based or land-based, mostly from a risk mitigation point of view: so we're less vulnerable to the environment and our staff are less vulnerable to the big lizards that are around,” Thépot explains.

The one exception is the grow-out site for the blacklip oysters – a project he inherited and kept on developing – which takes place in the sea, on long lines.

“It’s a project together with the Darwin Aquaculture Centre and a few other Aboriginal communities in the NT. We are still waiting on key documents from the government to be able to sell our oysters in Australia but the feasibility of growing oysters and shipping them back to Darwin and still be able to make a dollar on that needs to be more closely looked at. We think that a better alternative for us is to supply spats to other Aboriginal corporations in the NT and facilitating the growth of that industry, and this is why we’ve built a state-of-the-art hatchery,” Thépot explains.

Corruption allegations

One of the hardest times for the team was last year, when the previous CEO of the Anindilyakwa Land Council became the focus of an investigation into corruption.

“During that time we were really in a state of limbo. We didn't know if we were going to have a job tomorrow, but now we can start to see the light at the end of the tunnel,” Thépot reflects.

Otherwise his key challenges are largely related to logistics, as well as operating and maintaining a state-of-the-art RAS facility.

“We've got all the bells and whistles: all the filters, all the things that make RASs work in terms of biosecurity and production and being able to modify and control the water quality parameters. But it's really hard to set that up in the middle of nowhere, let alone when that middle of nowhere is a five-day barge trip from Darwin, as the cost of shipping is pretty horrendous. And don’t get me started with delays, shipments taking 2-3 months, some parcels are lost then found (if lucky)... That said, with challenges come opportunities if you look hard. We’re lost in the Gulf of Carpentaria – yes – but that means we have pristine water quality, no human influence and a stunning number of aquatic species to work with. Lastly, we’re growing products that have rich Anindilyakwa culture in them,” he notes.

Key breakthroughs

Amidst the tribulations there have also been triumphs.

“Breeding blacklip oysters and being able to mature the broodstock has been our biggest breakthrough – there's no commercial supplier in the world. It's a new species of tropical rock oyster [in terms of aquaculture] that has a lot of potential but to be able to have an industry you need to have spat,” Thépot explains.

“The first thing we needed to do was learn how to domesticate broodstock so we could have monthly spawns, because [under natural conditions] they only spawn during the summer. We had to establish everything from growing the microalgae, to optimising water quality and temperature, to working out the diurnal cycles. That was a big tick for us. Now the next thing is improving the spat survival, settlement and production, which we haven't really played enough with quite yet,” he adds.

Thépot initially planned to spend the first two years focusing on R&D, due the wide range of species and trials required, as well the need to start breeding programmes. However, the project is slowly pushing towards commercialisation.

“Last month we had our first sale of seaweed and we're looking at ramping up a couple of different things like the mullet and mud crab fisheries. We'd be easily breaking even in less than a couple of years. But we need to sustain and then improve that model after the royalties have ended,” he notes.

Thépot has had to work hard to land grant funding to tie the project over, but aims to increase the project’s revenues too.

“The ultimate goal is to have a company that can provide economically and socially to Groote Eylandt once the mine goes to facilitate that economic, social and environmental transition from mining era towards something that is a bit more sustainable and blue,” he reflects.

And he knows that imbuing the emerging generation with an enthusiasm for aquaculture is vital for achieving a lasting legacy.

“What I really want to achieve is planting the aquaculture seed in the minds of young people: talking to schools, increasing the visits to the site here, putting a third aquaponic system on Groote Eylandt into one of the community schools that we’ve yet to work with to expose them to the simple concepts of water quality, recirculation and biology. Because there's no point having a successful aquaculture business here for the traditional owners without the traditional owners being involved,” he emphasises.

“The question now is how do we pass on that aquaculture virus to other communities? So it spreads like wildfire and people start replicating and doing similar things in their own backyards?” he concludes.